As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOTHROTTLES WILL NOT STAY ENGAGED FOR MORE THAN 5 SECONDS AND THE THEY DISENGAGE. FOR THE 5 SECS THEY ARE ENGAGED THE THROTTLES ARE SPLIT. NO OTHER ABNORMALITIES WERE NOTED ON ANY FMC OR OTHER ACFT INSTRUMENTS. ALL CIRCUIT BREAKERS WERE CHECKED ALSO. ACFT GROUNDED. VERIFIED DISCREPANCY. A/T LOGGED SEVERAL "ASM 1" FAULTS. REPLACED NR 1 AUTOTHROTTLE SERVO MOTOR REF MM 22-31-91. INSTALLATION TEST NORMAL, REF MM 22-31-91.